package com.jy.modules.cims.common.sysUtils;

import java.text.MessageFormat;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * @description 以静态变量保存Spring ApplicationContext,
 *              可在任何代码任何地方任何时候取出ApplicaitonContext。
 * @version v1.0
 * @author ShengZhoutao
 * @Date 2015-3-17
 */
@Component
public class SpringContextUtils implements ApplicationContextAware,
		DisposableBean {
	private static final Logger logger = LoggerFactory
			.getLogger(SpringContextUtils.class);

	private static ApplicationContext applicationContext = null;

	/**
	 * 取得存储在静态变量中的ApplicationContext.
	 */
	public static ApplicationContext getApplicationContext() {
		assertContextInjected();
		return applicationContext;
	}

	/**
	 * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 */
	@SuppressWarnings("unchecked")
	public  <T> T getBean(String name) {
		assertContextInjected();
		return (T) applicationContext.getBean(name);
	}

	/**
	 * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 */
	public  <T> T getBean(Class<T> requiredType) {
		assertContextInjected();
		return applicationContext.getBean(requiredType);
	}

	/**
	 * 清除SpringContextHolder中的ApplicationContext为Null.
	 */
	public static void clearHolder() {
		logger.debug(MessageFormat.format(
				"清除SpringContextHolder中的ApplicationContext:{0}",
				applicationContext));
		applicationContext = null;
	}

	/**
	 * 实现ApplicationContextAware接口, 注入Context到静态变量中.
	 */
	public void setApplicationContext(ApplicationContext applicationContext) {
		if (SpringContextUtils.applicationContext != null) {
			logger.debug(MessageFormat
					.format("SpringContextUtil中的ApplicationContext被覆盖, 原有ApplicationContext为:{0}",
							SpringContextUtils.applicationContext));
		}

		SpringContextUtils.applicationContext = applicationContext; // NOSONAR
	}

	/**
	 * 实现DisposableBean接口, 在Context关闭时清理静态变量.
	 */
	public void destroy() throws Exception {
		SpringContextUtils.clearHolder();
	}

	/**
	 * 检查ApplicationContext不为空.
	 */
	private static void assertContextInjected() {
		if (applicationContext == null) {
			logger.error("applicationContext == null,applicaitonContext属性未注入, 请在applicationContext.xml中定义SpringContextUtils.");
		}
	}
}